Counterbalanced cap for arbor supports



Jan. 13, 1959 J. M. WALTER COUNTERBALANCED CAP FOR ARBOR SUPPORTS Filed Aug. 1'7, 1954 INVENTOR. JOHN M #2475? RT'I'ORNEYS.

COUNTERBALAN CED CAP FOR ARBOR SUPPORTS John M. Walter, Cincinnati, Ohio, assignor to The G. A. Gfiay Company, Cincinnati, Ohio, a corporation of io Application August 17, 1954, Serial No. 450,478

4 Claims. (CI. 90-11) This invention relates to a counterbalanced cap for arbor supports. In the use of horizontal boring, milling and drilling machines it is often desirable and even necessary to use an outboard support for the arbor particularly for extremely accurate or heavy duty work. Horizontal boring, milling and drilling machines are manufactured in various types, such as the planer type, floor type and table type, and regardless of the type of machine in question outboard arbor supports frequently must be used.

Such outboard supports generally comprise a body embodying approximately one-half of the cylindrical arbor support and a hinged cap constituting approximately the other half thereof. The body is mounted upon a column upon which it maybe adjusted as to its vertical position. It will, of course, be understood that the outboard support must be strictly coaxial with the spindle in use.

In very large machines of the type in question the hinged cap is too heavy to be opened and closed manually. In general practice the hinged cap is handled by means of a crane. This results in a great deal of dead time since the crane will often be occupied in another part of the shop.

With the foregoing considerations in mind it is an object of my invention to provide a counterbalanced cap for arbor supports so that the cap can be operated with relative ease by a single operator. 7 It is another object of the invention to provide a counterbalancing linkage such that the cap will be properly counterbalanced in any position between full open and full closed.

Other objects of the invention include the provision of a counterbalancing mechanism which is relatively simple and inexpensive and which may not only be incorporated in machines hereafter built, but may readily be adapted to machines now in existence.

These and other objects of my invention which I shall point out in greater detail hereinafter or which will be apparent to one skilled in the art upon reading these specifications, I accomplish by that certain construction and arrangement of parts of which I shall now describe an exemplary embodiment.

Reference is made to the drawings forming a part hereof, and in which:

Figure 1 is a fragmentary side elevational view of an arbor support and a column on which it is mounted with parts broken away and showing the cap in full open position.

Figure 2 is a top plan View of the same.

Figure 3 is a view similar to Figure 1 but showing the cap in full closed position, and

Figure 4 is an elevational view as seen from the right of Figure 3.

Arbor supports such as are discussed herein are conventionally counterbalanced by means of a cable secured to the support and passing over pulleys mounted in the column and secured to a weight. In the conventional nited States Patent 1 ice construction the weight has been equal to the entire weight of the arbor support including its hinged cap.

Briefly in the practice of my invention I provide a link secured to the arbor support and a linkage connecting said link to the hinged cap. A counterbalancing weight is secured to the link by means of a cable passing over a pulley in such manner that as the cap is opened and its moment increases, the effective moment of said weight is correspondingly increased. Further, the weight of the counterbalance of the arbor support as a whole is reduced by the amount of weight necessary to counterbalance the cap so that actually the cap is individually counterbalanced and the entire arbor support is also counterbalanced.

Referring now in greater detail to the drawings, the column on which the outboard arbor support rides is indicated at 10. The arbor support proper is indicated at 11, and the hinged cap is indicated at 12. The cap 12 is pivoted to the arbor support at 13.

The arbor support is partially counterbalanced by means of a cable 14 secured to the support 11 and pass ing over pulleys 15 and 16 mounted in the column and secured to a weight 17.

According to the present invention a link 18 is pivotally secured to the arbor support 11 at 19 and an elongated link 20 is connected pivotally at 21 to the link 18 and at 22 to the cap 12. A cable 23 is connected at 24 to the link 18 and passes over the pulleys 25, 26 and 27 and is secured to a weight 28.

It will be seen that as the cap 12 pivots about the point 13 in a clockwise direction the link 18, by virtue of the connection through the link 20, is also caused to pivot in a clockwise direction about the point 19. Thus the cable 23 is moved from a vertical position as in Figure 3 to the angular position of Figure 1 and thereby the effective moment of the weight 28 is made to vary in accordance with the effective moment of the cap 12.

As best seen in Figure 3 a lug 12a which may be integral with the cap 12 provides a stop to abut against the surface 11a on the member 11 to limit the opening of the cap 12 to the position shown in Figure l. The cap 12 is maintained in its closed position by means of bolts 30 in conventional manner. Lugs 31 are provided with holes through which a bar 32 extends to provide a handle element for the cap.

I have shown a sleeve or bushing 33 which may be slipped over the arbor 34 before the arbor is placed in position in the arbor support as shown in broken lines in Figure 1.

The member 11 and the column 10 are provided with the mutually cooperating ways as is well known, and conventional clamping means (not shown) are provided for clamping the member 11 to the member 10.

From the above description it will be clear that the arbor support 11 including the hinged cap 12 and all the associated parts are counterbalanced by the two weights 17 and 28 so that the entire unit may be adjusted with ease. When the arbor support has been adjusted to its desired position it will be seen that the weight 28 counterbalances the hinged cap which may thus be handled by a single operator with ease.

It will be understood that numerous modifications may be made without departing from the spirit of the invention; thus, for example the term weight is intended to be inclusive of a spring; and I therefore do not intend to limit myself except as set forth in the claims which follow.

Having now fully described my invention, what I claim as new and desire to secure by Letters Patent is:

1. In an arbor support for machine tools, said arbor support having a hinged cap, a weight of suflicient magnitude to counterbalance the weight of said support less saidhinged cap, and a second weight of sufficient mag nitude to counterbalance the weight of said hinged cap only, said two weights together being of sufficient magnitude to counterbalance the weight of the entire arbor support, said second weight being connected to said support and said cap by means of a multiplying linkage to compensate-for changes in moment of said cap in moving between full open and closed positions.

2. In an arbor support having a hinged cap, and mounted on a column of a machine tool, a first link pivotably secured to said support, a connecting link pivotablysecured to said first link and to said cap, a cable secured to said first link and passing over a pulley mounted on said column, and a weight secured to said cable, said cable and said first linktbeing in substantially colinear vertical alignment in the closed position of said cap, whereby as said cap swings open and its moment increases, said first link swings away from said alignment to correspondingly increase the eflective moment of said weight.

3. In an arbor support having a hinged cap and mounted on a column of a machine tool, a cable secured to said support, a pulley mounted on said column, said cable passing over said pulley and having a weight secured thereto ofsufiicient magnitude to counterbalance the weight of said arbor support less said hinged cap,-a counterbalancing linkage for said cap including a second-cable passing over a second pulley mounted on said column and secured to a second weight of sufiicient magnitude to counterbalance said hinged cap-during opening andclosing movementthereof, the magnitude of said two weights combined being sufficient to-counterbalance said entire arbor support, a first link pivotably secured to said support, said second cable being secured to the free end of said first link, said first link and said second cable being substantially in vertical colinear alignment in the closed position of said cap, a connecting link pivotably secured to said free end of said first link and also pivotably secured to said cap, whereby as said cap swings open and its moment increases, said connecting link moves said first link out of said alignment with said second cable, thereby correspondingly increasing the effective moment of said second weight.

4. In an arbor support having a hinged cap, and mounted on a column of a machine tool, a cable secured to said support, a pulley mounted on said column, said cable passing over said pulley and having the weight secured thereto, said weight being of sufficient magnitude to counterbalance the weight of said arbor support less said hinged cap, a first link pivotably secured to said support, a connecting link pivotably secured to said first link and to said cap, a second cable secured to said first link and passing over a second pulley mounted onsaid column, and a weight secured to said second cable, said second cable and said first link being in substantially colinear vertical alignment in the closed position of said cap, whereby as said cap swings open and its moment increases, said first link swings away from the vertical to increase correspondingly the efiective moment of said second weight, said weights together being of a magnitude tocounterbalance said entire arbor support.

References Cited in the file of this patent UNITED STATES PATENTS 214,035- Harrington Apr. 8, 1879 563,610 Northrop July 7, 1896 1,669,915 Rusnak May 15, 1928 2,065,099 Romaine et a1. Dec. 22, 1936 2,364,318 Schauer Dec. 5, 1944 2,370,384 1 Williamson Feb. 27, 1945 2,375,408 Gallimore et a1. May 8, 1945 2,464,415 Phillippe Mar. 15, 1949 2,679,442 Koerner et a1. May 25, 1954 

